The film tracks protagonist Chen Zhihui who succumbs to trauma and frustration when he is released after spending 20 years in prison and becomes a serial killer. The film tracks protagonist Chen Zhihui who succumbs to trauma and frustration when he is released after spending 20 years in prison and becomes a serial killer. The film tracks protagonist Chen Zhihui who succumbs to trauma and frustration when he is released after spending 20 years in prison and becomes a serial killer. The film tracks protagonist Chen Zhihui who succumbs to trauma and frustration when he is released after spending 20 years in prison and becomes a serial killer.